Topic: Turbochargers

[dwtaylorpdx]

One issue with the TB before the turbo is it will reverse flow
the exhaust from the cylinders during valve overlap. If you need/want
the TB before the turbo it requires a special cam grind to close the intake
before the exhaust opens.  Which impacts power etc. Not worth the trouble imho.

You can get away with it on a supercharger becasue of the mechanics of it
and the bypass valve makes it act like a regular intake during off throttle operation.

Dave

[st.chevrolet]

That is for sure, but BIG problems start exactly after everything is easily put on. Never read no thread ending up happily. In super charger setup, as they say, all you need to do after hardware installation - put computer in to learn mode, and enjoy. In turbo mods after installation you have to meet the endless screwing with fake electronic devices and injectors selection. May thats why there is no turbo kits on the market, I don't know.

Not sure where you are getting your info from or what threads your reading, but the above statement is totally untrue. You won't be putting your Jeep computer in any "learn mode", and the "fake electronic devices and injectors selection" are also required with superchargers. And kits are available from 505 Performance.

[sharpxmen]

You won't be putting your Jeep computer in any "learn mode", and the "fake electronic devices and injectors selection" are also required with superchargers.

x2
same deal with superchargers as with turbos

[Vodkaman]

I've got my info from Avenger SC installation manual.  "39. It is time to place the factory computer into learn mode for the newly installed Supercharger. Step 1. Key Ignition ON / Step 2. Headlights ON / Step 3. Headlights OFF / Step 4. Key OFF."
You think they lie?
From 505 Performance only one kit is available - for 4L, and it costs a lot.
And I'm talking not about turbo against SC, I made my choice, I'm talking about the fact, that in each turbo setup (including yours Mr. St.Chevrolet :)) there is no end, no Dyno test, no certain recommendations of how it should be done.
But never the less I'm going to build my turbo 2.4 tj too, and just asking for advice. :):)

[Vodkaman]

Got another stupid question: - What  will happen if stock MAP sensor is placed on vacuum side of compressor?

[sharpxmen]

I've got my info from Avenger SC installation manual.  "39. It is time to place the factory computer into learn mode for the newly installed Supercharger. Step 1. Key Ignition ON / Step 2. Headlights ON / Step 3. Headlights OFF / Step 4. Key OFF."
You think they lie?
From 505 Performance only one kit is available - for 4L, and it costs a lot.
And I'm talking not about turbo against SC, I made my choice, I'm talking about the fact, that in each turbo setup (including yours Mr. St.Chevrolet :)) there is no end, no Dyno test, no certain recommendations of how it should be done.
But never the less I'm going to build my turbo 2.4 tj too, and just asking for advice. :):)

that only works for closed loop, at wide open throttle and open loop it won't help at all. On top of that the stock MAP is only good for normally aspirated engines, once you get in boost it will only report up to sea level pressure (1 bar). Same is valid for a turbo application, so Sean was correct - there is no difference between turbo and s/c when comes to fuel management (or to put it this way they both work based on same principle, there are differences but not fundamental). this is a long discussion, there are a bunch of threads on this site where you can find a lot of information on what you need to do to have the mixture with the right amount of air and fuel. Dyno time costs money.

Got another stupid question: - What  will happen if stock MAP sensor is placed on vacuum side of compressor?

i wouldn't say it's a stupid question - the system that uses a MAP sensor (manifold air pressure) is called speed density and uses the rpm and the absolute air pressure in the intake manifold that feeds the cylinders - based on that the PCM/ECU calculates the amount of air (and therefore oxygen) that goes into the cylinders and adjusts the fuel delivery based on that - if you misplace the location of the MAP sensor port (and in your example it would be misplaced) the PCM / ECU will not be able to calculate the correct amount of air that the cylinders are "inhaling" so therefore the mixture will be off (or impossible to compensate with fuel if you wish) - basically the system will not have the right information.

the other system that you might have encounter is the MAF (mass air flow) and that is measuring the air flow (easy to guess) to gather the information regarding the amount of air that is going in the cylinders.

btw, Avenger ended up recommending a piggyback system for their supercharger kit. Kenne-Bell was flashing the Jeep PCMs with a new fuel and spark advance map (not the map sensor, map as in a table containing the rpm/pressure fuel delivery parameters or more specifically the injector duty cycle). both were using larger injectors. there are also other factors that affect fuel delivery like IAT (intake air temperature) and engine coolant temperature.

[Vodkaman]

Dyno time costs money.

Not that much as a modification. And it is made not only for knowing result, but mostly for fine tuning. Correct me if I'm wrong.

i wouldn't say it's a stupid question - the system that uses a MAP sensor (manifold air pressure) is called speed density and uses the rpm and the absolute air pressure in the intake manifold that feeds the cylinders - based on that the PCM/ECU calculates the amount of air (and therefore oxygen) that goes into the cylinders and adjusts the fuel delivery based on that - if you misplace the location of the MAP sensor port (and in your example it would be misplaced) the PCM / ECU will not be able to calculate the correct amount of air that the cylinders are "inhaling" so therefore the mixture will be off (or impossible to compensate with fuel if you wish) - basically the system will not have the right information.

the other system that you might have encounter is the MAF (mass air flow) and that is measuring the air flow (easy to guess) to gather the information regarding the amount of air that is going in the cylinders.

On 2,4 TJ as far as I know we have both MAP and MAF sensors. Does it make a difference?

btw, Avenger ended up recommending a piggyback system for their supercharger kit. Kenne-Bell was flashing the Jeep PCMs with a new fuel and spark advance map (not the map sensor, map as in a table containing the rpm/pressure fuel delivery parameters or more specifically the injector duty cycle). both were using larger injectors. there are also other factors that affect fuel delivery like IAT (intake air temperature) and engine coolant temperature.

As I understood the operation of most piggyback systems is to fool stock ECU, and in most cases they work through MAP sensor inlet. You can not fake amount or temperature of the air, but you can pretend that you are far above sea level and force ECU to compensate low density with additional amount of fuel. Is that correct?

[sharpxmen]

Not that much as a modification. And it is made not only for knowing result, but mostly for fine tuning. Correct me if I'm wrong.

you don't need a dyno to fine tune - if you have the tools to monitor and log the engine operating parameters you can do it on the street.

On 2,4 TJ as far as I know we have both MAP and MAF sensors. Does it make a difference?

first time i hear this but i am not familiar with the 2.4 - i don't see the point in having both, but then again i dunno anything about this engine. It makes a difference since with the stock 1 bar MAP you are limited in measuring up to sea level pressure, with a MAF you will get information about the extra amount of air that makes it into the engine even in boost (all air flow, not pressure)

You can not fake amount or temperature of the air, but you can pretend that you are far above sea level and force ECU to compensate low density with additional amount of fuel. Is that correct?

there is no point in faking the IAT output although Avenger recommended moving the IAT sensor before the s/c (i think it was Avenger, or maybe another kit brand that i read about) once you compress the air it will raise the air temp - higher Air Temp will retard the spark and reduce the amount of fuel that is delivered (less dense air) but that is only valid in open loop, in closed loop works by means of O2 feedback

lower air density means less fuel required (higher altitude, less density => less oxygen to burn fuel) - the other way around

As I understood the operation of most piggyback systems is to fool stock ECU, and in most cases they work through MAP sensor inlet.

you're right about the piggyback modding the map output or replacing it with their internal one - same goes for the MAF output. In the case of the map there is another twist - your stock map works up to 1 bar, the piggyback systems come with a 2 bar or even a 3 bar internal map sensor, so basically replaces the limited stock MAP with one that can read intake pressure in aspirated mode as well as in boost mode. With MAF you mod the voltage output so you reduce the AFR (increase fuel) during boost. Same here, all this is valid for open loop, you cannot adjust the AFR in closed loop by changing the MAP or MAF output - the PCM will always compensate targetting 14.7 AFR - you will need a way to either put the PCM/ECU in open loop or mod the O2 output in that case (14.7 is too lean when you're in boost).

some piggyback systems are also controlling ignition advance (more specifically will retard timing) - this is due to compressing the air and increasing the air temperature and the result is burning the fuel faster so less timing advance required - this will not address detonation however which will cause knocking/pinging (mixture autoigniting).

[Vodkaman]

I was wrong about MAF on 2,4l TJ. There is no MAF, just MAP, IAT and TPS. Also with altitude compensation you are right. In Avenger manual I have, they say nothing about IAT relocation, and you are right again  PCM must see real temperature of the air taken inside. So, what to do? 

[sharpxmen]

I was wrong about MAF on 2,4l TJ. There is no MAF, just MAP, IAT and TPS. Also with altitude compensation you are right. In Avenger manual I have, they say nothing about IAT relocation, and you are right again  PCM must see real temperature of the air taken inside. So, what to do? 

what do you want to achieve? what's your planned application - turbo, s/c? what's your desired boost?

[Vodkaman]

The aim is very simple to be as close to 6 banger as possible. Which means torque maximum at 2500-2800 rpm, and 140-150 whp.
Low boost turbo, up to 8 psi. TD04L - 16G with air to air intercooler, biger injectors and ?? smth to manage a/f ratio.

[sharpxmen]

The aim is very simple to be as close to 6 banger as possible. Which means torque maximum at 2500-2800 rpm, and 140-150 whp.
Low boost turbo, up to 8 psi. TD04L - 16G with air to air intercooler, biger injectors and ?? smth to manage a/f ratio.

have a look at AEM FI/C - from what i remember is meant for OBDII systems and i think you can also alter the O2 output to get the best out of it in closed loop. Also, i think in your case there was a Chrysler vehicle that had a turbo on the same engine (PT Cruiser i think) so it might be that you can find an exhaust manifold to mount a turbo on it.

here's a good writeup for you, very interesting - same engine as yours i believe http://www.reno4x4.com/forum/showthread.php/5362-Turbocharged-2.4L-Jeep-TJ-for-me!!!
 

[chardrc]

someone on here used to (maybe still does) have a turbo 2.4l i think he had to keep the jeep block for the motor mounts to work but had to install the exhaust manifold from the turbo 2.4l upside down to get everything to fit..

[Vodkaman]

As I said, I been through all threads available in internet, but none of them ended happily. No one wrote down a total list of parts, and any dyno results.
In my case, to make hardware not a big deal. Tuning - that is the problem. Any stand alone like AEM, is definitely out of budget.
Maximum PSC1-002 from Split Second.

[sharpxmen]

As I said, I been through all threads available in internet, but none of them ended happily. No one wrote down a total list of parts, and any dyno results.
In my case, to make hardware not a big deal. Tuning - that is the problem. Any stand alone like AEM, is definitely out of budget.
Maximum PSC1-002 from Split Second.

you can use the PSC1 to start with and later add an ignition timing retard module if you find that knocking is an issue (trying not to be biased here but i do have an MSD/Vortech unit for sale in the garage sale section for $75 if you're interested - i ended up with the Split Second FTC1 so that addresses the timing also).